Adjustable fused plug



March 25, 1958 A. E. SLAWIK ADJUSTABLE FUSED PLUG 2 Sheets- Sheet 1 Filed Feb. 24, 1954 21,50 17 A/berz E. Slaw/k BY %M OWQMM INVENTOR ATTORNEY March 25, 1958 A. E. SLAWIK ADJUSTABLE FUSED PLUG 2 Sheets-Sheet 2 Filed Feb. 24, 1954 BY I YAZTTORNEY United tates Patent ,2

ADJUSTABLE FUSED PLUG Albert E. Slawik, St. Paul, Minn.

Application February 24, 1954, Serial No. 412,215 8 Claims. c1. zoo-11 5.5

This invention relates to an improvement in adjustable plugs which are of the type used to connect electrical appliances with suitable sockets to provide a connection from the appliance to a source of supply of electricity.

An object of the present invention resides in the provision of a plug which contains fuses so that the main fuse of the circuit Will not be blown in the event of a short circuit in the appliance. Main fuses must be heavy enough to permit a relatively heavy current to'fiow into the circuit due to the fact that numerous electrically operated lights, appliances and the like are often simultaneously operated on the same circuit. Therefore, when a short circuit occurs, considerable heat is generated. By providing fuses in plugs attached to any single appli ance, the fuses employed can be of smaller size as only enough current must fiow to operate the single appliance. Therefore, in the event of a short circuit, much less heat may be generated.

A feature of the present invention lies in the provision of a plug which supports a cord in such a manner that the cord may always extend downwardly from the plug. Plugs of most types are elongated in the direction of the prongs of the plug and thus project a substantial distance from the wall. Some plugs have been produced in which the cord projects from the plug on a plane parallel with the wall in which the socket is mounted. However, such plugs may support the cord to extend horizontally or vertically from the plug, depending upon the position of the socket into which the plug is inserted. In the present structure, the prongs may be adjusted so that the cord may always extend in a desired direction from the plug. In other words, if desired, the cord may always hang downwardly from the plug along a line parallel with the wall, thereby preventing the plug from being accidentally disengaged.

A feature of the present invention lies in the provision of a plug having a pair of prongs which are adjustable in position. The distance between the prongs of the plug is so arranged that both prongs cannot accidentally be secured to the same terminal within the body of the plug, thereby causing a short circuit when the plug is inserted into the socket. The arrangement is such that if the prongs are improperly positioned, the plug cannot be inserted into the socket.

Added features are also provided such as the simplicity of construction and the economy of production. The structure has been carefully designed from a safety stand point so as to prevent the likelihood ofshort circuits. The device is simple in construction and can be produced at low cost.

These and other objects and novel features of the invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of the specification:

Figure l is a front elevational view of my plug.

Figure 2' is a view similar to Figure l with the cover portion thereof removed.

2,828,387 Patented Mar. 25, 19 58 Figure 3 is a rear elevational view of the plug.

Figure 4 is a sectional view through the body of the plug with the cover portion removed, the position of the section being indicated on the line 4-4 of Figure 2.

Figure 5 is a sectional view on the line 55 of Figure 2.

Figure 6 is a side elevational view of the complete plug.

Figure 7 is a sectional view on the line 77 of Figure l.

Figure 8 is a prospective view of one of the plug prongs.

Figure 9 is a prospective view of one of the plug parts.

Figure l0 is a prospective view of another of the plug parts.

The plug is indicated in general by the letter A and is shown as including a body portion which is indicated in general by the numeral 10 and a cover portion which is indicated in general by the numeral 11. These two parts it) and 11 interfit together and form an enclosure for the various parts. The body portion 10 includes a mounting plate 12 having a short rearwardly projecting boss 13 on its rear surface. A top flange 14 extends at right angles to the mounting plate 12 and acts as an end closure for the plug. A downwardly projecting lip 15 is provided extending along the forward edge of the flange 14 for overlapping the cover portion 11 when the two parts are assembled.

As is best shown in Figures 2 and 7 of the drawings the body portion It) is provided with a pair of parallel guides 16 and 17 extending near opposite edges of. the base plate 12. The guides 16 and 17 are shown in Figure 7 to include parallel grooves 19 and 20 respectively in their outer surfaces. These grooves extend virtually throughout the length of the guides 16 and 17.

The cover portion 11 includes a front cover plate 21 and side flanges and 23. The side flanges are provided with inwardly projecting ribs 24 and 25 which are designed to extend into the grooves 19 and 20. In other words, the cover portion slides onto the base portion and ribs on the cover portion extend into co-operable grooves of the base portion.

The guides 16 and 17 are also provided with indentations 26 and 27 respectively. Co-operable projections 29 and 3b are provided on the flanges 22 and 23 of the cover 11. When the cover is fully telescoped onto the base portion, the projections 29 and 30 extend into their co-operable recesses 26 and 27 to hold the parts as sembled. The material forming the plug is sufficiently resilient so that the projections 29 and 30 may be forced apart a distance sufficient to permit the parts to be assembled.

As is also shown in Figure 7, a central rib 31 is provided on the base panel 12, this rib acting as a separator for the two terminal portions of the plug. In closed position of the plug, the rib 31 acts to divide the interior of the plug into two spaced compartments as designed to accommodate a fuse.

As is also shown in the drawings the base plate 12 is tapered inwardly along rounded outlines to form a restricted lower end portion 32. The cover 11 is similarly shaped so as to provide a restricted U-shaped portion 33 at its lower extremity through which the cord may extend. The body 10 of the plug is provided with contact members which are embedded therein. Two of these contact members are shown in Figures 9 and 10 of the drawings. The contact member 34 shown in Figure 9 includes a plate 35 which fits on the inner surface of the mounting plate 12 and which is provided with two headed projections 36 which are embedded into the plastic forming the plate 12 during the molding thereof. A split ring 37 is also secured to, or is integral with the plate 35.

' through 66. These recesses 67 are of assess? This split ring 37 is designed to partially encircle one end of a fuse such as 39 to hold the fuse end in place.

The plate is of suflicient width to extend from the center of one fuse compartment between the guide 16 and the centerflange 31 and the center line of the plug. An opening 40 is provided which is aligned with the center of the fuse compartment and a second opening 41 is provided which is normally located at the vertical center line of the plug. A second terminal structure shown in Figure 10 is illustrated in general by the numeral 42. The terminal 42includes a fuse encircling split ring structure 43 designated to engage one end of a fuse 44. The terminal 42 also includes a plate 45 which extends along the inner surface of the mounting plate 12 and is partially embedded within the rib 31. Headed pins 46 are provided on the plate 45 by means of which the terminal may be anchored into the plastic or rubber of which the plug is formed. The plate 45 is provided with an opening 47 which is aligned with the center of the fuse compartment between the flange 17 and the rib 31. The plate 45' is elongated and is provided with a second opening 49 which is located on the center line of the plug.

It will be noted that the openings 40 and 41 are relatively close together and the openings 47 and 49 are relatively far apart. The purpose of this arrangement will be more specifically described.

A second terminal is provided in each of the fuse chambers, these terminals being substantially similar in form and design and being best illustrated in Figures 2 and 4 of the drawings. As the two terminals 50 and 51 are identical, the corresponding parts thereof will be similarly numbered I Each'terrninal includes a plate 52 having a forwardly projecting ear 53 at its, lower extremity. Each plate 52 is provided with a threaded aperture to accommodate a terminal bolt 54 which may be entirely removable or may belocked from removal. A forwardly projecting ear 55 is provided above the bolts 54 and each plate is provided with a split ring shaped portion 56 near its upper extremity for accommodation of the lower end of a corresponding fuse.

As shown in Figure 4 each of the terminals is provided with a headed projection 57 which is embedded into the base plate 12 to hold the terminalin place. The ears 53 and 55 act to assist in holding a conductor encircling the shank of the terminal bolts or screws 54.

As indicated in Figure 8 of the drawings the plug prongs 59 are detachable; Each prong 59 includes an elongated, thin strip 60 of proper dimensions to fit within a socket of usual design and the prongs are likewise provided with a base 61' which is preferably square, hexagonal or the like. A threaded socket 62 is provided in the end of the base 61 with its axis on, or parallel to, the axis of the shank 69.

In the formation of the plug; the terminals 34, 42, 5t and 51 are preferably embedded into the material during the molding operation. Also during the molding operation, openings 63 and 64 extend through the plate 12 in alignment with the threaded apertures 40 and 47 relatively of the terminals 34 and 42 Openings 65 and 66 are likewise molded into the plate 12 in alignment with the threaded openings 41 and 49 of the terminals 34 and 42. On the rear surface of the plug body 16 rectangular recesses 67 are provided surrounding each opening 63 proper size to accommodate the base 61 of a prong 59. The square shaped or other shape of the recess is such as to'prcvent the twisting of the prong when in place in a'recess.

In Figure 3 of the drawings it Willbe noted that the openings63 and 64 are transversely aligned and the openings 65 and 66 are vertically aligned, each pair of openings being a similar distanceapart. Accordingly, the prongs 59 may be attached in either pair of positions, he r n s either be ng msunt gttnregi rr h'the p nlugs 63 and 64 or in registry with the openings 65 and 66. If the socket apertures in the socket into which the plug extends are laterally spaced, the prongs are inserted into the openings 63 and 64. On the other hand, if the socket openings are vertically spaced, the prongs are inserted into the openings 65 and 66.

As is seen in Figure 3, the dissimilar shape of the terminals 3 3 and 42 position the opening 65 much closer to the openings 63 and 64 than to the opening 66. As a result if the prongs were inserted in the openings 63 and 65 which nnected to the same terminal the prongs are not parallel and also the prongs are too close to be inserted into the socket. At the same time if an attempt is made to mount the prongs in the openings 64 and 66, the prongs are too far apart to fit into the socket and also are not parallel. Thus, it is virtually impossible to improperly mount the prongs and still provide an operative device. A pair of lugs 69 are provided on the flanges 22 and 23 by means of which the plug may be handled, these lugs aiding in the assembly of the cover onto the body portion. As is shown in Figures 4 and 5 of the drawings, short bolts or cap screws 79 are provided for holding the prongs 59 in place and for forming an electrical connection with the terminals to which they are attached. Figure 4 shows the prongs 5? in laterally spaced position, while Figure 5 shows the prongs in vertically spaced relation. T The operation of the construction is believed obvious from the foregoing description. The line wires enter the restricted end 33 of the plug, one line wire being secured to the terminal 59 and the other line wire being secured to the terminal 53. The; terminals as and 42 are, in turn, connected to the prongs of the plug and the only electrical connection between the terminals 34 and 42 and the corresponding terminals 56 and 51 extends through the fuses 39 and 44. Thus the prongs may be adjusted to a position in which the restricted and of the plug body may permit the cord to downwardly regardless of the arrangement of the socket openings.

In accordance with the patent statutes, I have described the principles of construction and operation of my adjustable plugs and while I have endeavored to set forth the best embodiment thereof, 'I desire to have it understood that obvious changes may be made within the scope of the following claims Without departing from the spirit of my invention. a

I claim:

1. A plug includingin combination a body portion and a cover portion. the body portion including a mounting plate, an end flange secured at one end of said plate and side flanges extendin in parallel relation along opposite sides of said body,the-cover portion including a panel opposite said mounting plate and side flanges thereon, cooperable interengaging slide means on the side flanges of said cover portion and the side flange of said body portions for slidably connecting said portions for relative longitudinal slidable movement, terminals within said body portion between said base plate and said cover panel, adjustable prongs connect d to said terminals, and fuse means connecting said prongs to said terminals.

2. The construction described in claim land including locking means co-operable between said cover portion and said body portion for holding said portions assembled.

3. A plug including a hollow elongated body, an elon gated mounting plate forming one side of said body, a pair of terminal plates secured 'to the surface. of said mounting plate within said body, fuse end supporting means on each of said terminal plates at one end of said mounting plate, each of said terminal plates including. a portion extending across the longitudinal center line of said mounting plate, said terminal plates being in spaced relation, a pair of openingsv in each of said terminal plates, one opening in each plate being at said center line and the other openings being transversely aligned on opposite side sf' h tent lies a ir assd u po t terminals secured to said mounting plate in longitudinally spaced relation to said fuse end supporting means on said supporting plates, fuses extending between said fuse end supporting means and said fuse supporting terminals, prongs, and means extending through a selected opening of each terminal plate and through said mounting plate for securing said prongs to said terminal plates, a central rib on said mounting plate between said fuses, said rib being notched at spaced points to accommodate said portions of said terminal plates.

4. A plug including a hollow elongated body, an elongated mounting plate forming one side of said body, a pair of terminal plates secured to the surface of said mounting plate within said body, fuse end supporting means on each of said terminal plates at one end of said mounting plate, each of said terminal plates including a portion extending across the longitudinal center line of said mounting plate, said terminal plates being in spaced relation, a pair of openings in each of said terminal plates, one opening in each plate being at said center line and the other openings being transversely aligned on opposite sides of the center line, a pair of spaced fuse supporting terminals secured to said mounting plate in longitudinally spaced relation to said fuse end supporting means on said supporting plates, fuses extending between said fuse end supporting means and said fuse supporting terminals, prongs, and means extending through a selected opening of each terminal plate and through said mounting plate for securing said prongs to said terminal plates, and in which the distance between the 9 openings at the center line equals the distance between the transversely aligned openings, but differs from the distance between the openings in either terminal plate.

5. A plug including a hollow elongated body, an elongated mounting plate forming one side of said body, a pair of terminal plates secured to the surface of said mounting plate within said body, fuse end supporting means on each of said terminal plates at one end of said mounting plate, each of said terminal plates including a portion extending across the longitudinal center line of said mounting plate, said terminal plates being in spaced relation, a pair of openings in each of said terminal plates, one opening in each plate being at said center line and the other openings being transversely aligned on opposite sides of the center line, a pair of spaced fuse supporting terminals secured to said mounting plate in longitudinally spaced relation to said fuse end supporting means on said supporting plates, fuses extending between said fuse end supporting means and said fuse supporting terminals, prongs, and means extending through a selected opening of each terminal plate and through said mounting plate for securing said prongs to said terminal plates, said hollow elongated body including a cover member lon gitudinally slidably secured to said mounting plate.

6. A plug including a hollow elongated body, an elongated mounting plate forming one side of said body, a pair of terminal plates secured to the surface of said mounting plate within said body, fuse end supporting means on each of said terminal plates at one end of said mounting plate, each of said terminal plates including a portion extending across the longitudinal center line of said mounting plate, said terminal plates being in spaced relation, a pair of openings in each of said terminal plates, one opening in each plate being at said center line and the other openings being transversely aligned on opposite sides of the center line, a pair of spaced fuse supporting terminals secured to said mounting plate in longitudinally spaced relation to said fuse end supporting means on said supporting plates, fuses extending between said fuse end supporting means and said fuse supporting terminals, prongs, and means extending through a selected opening of each terminal plate and through said mounting plate for securing said prongs to said terminal plates, said prongs including multi-sided ends, and said mounting plate including similarly shaped sockets to accommodate said ends of said prongs.

7. A plug including a hollow elongated body including a removable elongated mounting plate forming a side thereof, a pair of spaced terminal plates within said body against said plate, laterally spaced fuse end supporting means on said terminal plates, a pair of spaced fuse supporting terminals on the inner surface of said mounting plate in longitudinally spaced relation to said fuse end supporting means, fuses connecting said fuse end supporting means and said fuse supporting terminals, said terminal plates and mounting plate having apertures therethrough, square sockets in the outer surface of said mounting plate encircling said apertures, prongs having square ends thereupon of a size to engage in said sockets, and threaded means extending through said apertures and securing said prongs to said terminal plates.

8. The structure of claim 7 and in which each terminal plate and said mounting plate includes a plurality of similar apertures.

References Cited in the file of this patent UNITED STATES PATENTS 1,319,920 Benjamin Oct. 28, 1919 1,351,191 Sidon Aug. 31, 1920 1,968,213 Lofgren July 31, 1934 1,970,144 Kollath Aug. 14, 1934 2,668,885 Gerlat Feb. 9, 1954 

